Abstract: A digital map display zooming method for continuously enlarging and reducing a displayed portion of a digital map as map information in digital form within a display screen is provided which comprises the steps of displaying the displayed portion of the digital map at the display screen, displaying a scroll part within the display screen for shifting the displayed portion, making the scroll part function as a scale setting part for carrying out enlarging and reducing operations of the displayed portion of the digital map within the display screen, and carrying out enlarging and reducing operations of the displayed portion of the digital map within the display screen by shifting a shifting operation part of the scale setting part.

Abstract: An input device for a computer system includes a detection circuit with first and second inputs capable of carrying first and second input signals. A user depressible switch adapted to allow a user to interact with the computer system is placed in series with a rectification device between the two inputs. The rectification device being adapted to limit electrical current in a first direction between the first input and the second input.